6+(5+1)
(5+1)=6
6(6)
6x6= 36
We know that
applying the law of cosines
a² = b²+ c²<span> – 2*b*c*cos(A)
</span>
in this problem
a=?
b=20
c=9
A=90°
so
a² = b²+ c² – 2*b*c*cos(A)
but
cos (A)=0
a² = b²+ c²-----> 20²+9²----> a²=400+81----> a²=481-----> a=√481
a=21.93-----> a=22
the answer is
22
-2x+y=5
x-3y=-30 so you can multiply the bottom equation by 2 you'll get 2x-6y=-60
-2x+y=5
2x-6y=-60 And subtract the equations. You'll get -5y=-55 y=11. Plug it in to one of the original equations. -2x+(11)=5
-2x=-6 so x=3
y=11 and x=3
